Lewanczuk R Z, Chen A, Pang P K
Department of Physiology, University of Alberta, Edmonton, Canada.
Am J Hypertens. 1990 May;3(5 Pt 1):349-53. doi: 10.1093/ajh/3.5.349.
A high calcium intake has been shown to attenuate the degree of hypertension in spontaneously hypertensive rats (SHR) and some human hypertensives. Conversely, a low calcium intake has been associated with an increase in blood pressure in both groups. In the present study, the effects of a high (2%), medium (0.6%) and low (0.02%) calcium diet on mean arterial pressure (MAP) and on the expression of a novel circulating hypertensive factor--parathyroid hypertensive factor (PHF)--were examined in SHR. In rats on the low calcium diet, MAP and PHF activity were significantly higher at 8 weeks than in the other two groups. In the high calcium group, MAP was significantly lower than in the other two groups, although it was elevated compared to week 0 values. PHF activity was not detected in the plasma of this high calcium group. Overall, MAP was highly correlated with PHF activity (r = 0.78, P = .0001). These results suggest that the effects of dietary calcium on blood pressure in SHR may be mediated by a novel circulating hypertensive factor, PHF, such that a high calcium diet inhibits, and a low calcium diet stimulates, the expression of this factor.
高钙摄入已被证明可减轻自发性高血压大鼠（SHR）和部分人类高血压患者的高血压程度。相反，低钙摄入与这两组人群的血压升高有关。在本研究中，研究了高钙（2%）、中钙（0.6%）和低钙（0.02%）饮食对SHR平均动脉压（MAP）以及一种新型循环高血压因子——甲状旁腺高血压因子（PHF）表达的影响。在低钙饮食的大鼠中，8周时的MAP和PHF活性显著高于其他两组。在高钙组中，MAP虽比第0周的值有所升高，但显著低于其他两组。该高钙组血浆中未检测到PHF活性。总体而言，MAP与PHF活性高度相关（r = 0.78，P = 0.0001）。这些结果表明，饮食钙对SHR血压的影响可能由一种新型循环高血压因子PHF介导，即高钙饮食抑制该因子的表达，低钙饮食刺激该因子的表达。
